Issue paint invalidations before and after changing offsetFromRenderer and reconfiguring

LayoutTests/compositing/squashing/add-remove-squashed-layers-expected.txt

Index: LayoutTests/compositing/squashing/add-remove-squashed-layers-expected.txt
diff --git a/LayoutTests/compositing/squashing/add-remove-squashed-layers-expected.txt b/LayoutTests/compositing/squashing/add-remove-squashed-layers-expected.txt
index c8c2d16baca153b5c5abb7a554326e60ed093cb9..4518b9bb10f6fa38530ebb1ba1b65b5f2a3c372e 100644
--- a/LayoutTests/compositing/squashing/add-remove-squashed-layers-expected.txt
+++ b/LayoutTests/compositing/squashing/add-remove-squashed-layers-expected.txt
@@ -123,6 +123,7 @@ CASE 4, overlap1 gets removed:
               (bounds 100.00 100.00)
               (drawsContent 1)
               (repaint rects
+                (rect 160.00 160.00 100.00 100.00)
                 (rect 0.00 0.00 100.00 100.00)
                 (rect 0.00 0.00 100.00 100.00)
               )
@@ -163,7 +164,6 @@ CASE 5, overlap2 gets added back:
                 (rect 80.00 80.00 100.00 100.00)
                 (rect 0.00 0.00 100.00 100.00)
                 (rect 0.00 0.00 100.00 100.00)
-                (rect 0.00 0.00 100.00 100.00)
               )
             )
           )